Ferrari built a turbo that was too small, then spent most of a season pretending it was clever engineering rather than a miscalculation. At Monza this weekend, the second ADUO upgrade quietly admits the truth by fitting a bigger one.
Lewis Hamilton has already told reporters the upgrade will not close the gap to Mercedes, and that story has been told. What matters more is the engineering behind it, because it reveals exactly where Ferrari got its power unit philosophy wrong at the start of the year, and why fixing it mid-season was never going to be simple.
A Turbo Designed to Solve the Wrong Problem
When Enrico Gualtieri’s engine department drew up the SF-26 power unit, they went small on the turbocharger. The logic made sense on paper: a smaller-diameter turbo with less rotational inertia spools up faster, cutting the lag that traditionally hurts a car off the line. Quick reactions at the start, in theory, translate into places gained before Turn 1.
Except Formula 1 does not race off the line the way it used to. The PRE-START phase lets engines rev in neutral for five seconds before lights out, building turbo pressure artificially and erasing the very advantage Ferrari had designed for. All care taken to solve start-line lag was rendered pointless by a regulation that already solved it for everyone.
What Ferrari was left with was the downside without the upside. A smaller turbo produces less top-end power, and on the straights, where turbos matter most at high RPM, that shows up as a straight-line speed deficit. Hamilton put a number on it after the Dutch Grand Prix, telling reporters that Ferrari lost four tenths a lap to the pace-setters even on a short circuit. That is not a rounding error. That is a car that cannot fight for wins on power alone, and it has been true, in Hamilton’s words, “all year.”
What the Bigger Turbo Actually Changes
Under the FIA’s current rules, the ADUO system judges performance purely on the internal combustion engine, stripped of any contribution from the electrical side. That framework left Ferrari with a narrow but clear target for its allowance: fix the turbo, because that is the only lever the regulations let them pull.
Fitting a larger-diameter turbocharger is not a bolt-on tweak. It rewrites how the engine breathes, which changes combustion characteristics, ignition timing, fuel consumption, and the entire power and torque delivery curve. Every parameter that governs how the internal combustion engine behaves has effectively had to be recalibrated around the new hardware. Ferrari is not, technically, building a new engine. In practice, it might as well be.
There are knock-on effects for the electrical side too, even though that is officially outside the ADUO’s remit. A bigger turbo changes how much energy is available for harvesting under braking and through corners, which matters for how the MGU-H and the wider hybrid system are managed across a lap. None of that shows up in the FIA’s combustion-only metric, but it shapes how the whole power unit behaves on track.
The Numbers Behind the Claim
Bench test data, according to sources cited by RacingNews365, points to an increase of more than 2% in power from the internal combustion engine, helped by parallel refinements to Ferrari’s Shell fuel blend developed alongside the new turbo. Two percent does not sound dramatic until you remember Formula 1 is a sport where tenths of a percent routinely separate front row from fourth row.
Whether that translates into results is a separate question from whether the fix is real. It looks like a genuine correction of a design error rather than a marginal tweak, and Ferrari would not be reworking combustion, ignition and fuel chemistry simultaneously if the original turbo choice had been merely suboptimal rather than actively wrong.
Why This Is Really About 2027
Here is the part Ferrari would rather not dwell on publicly: this upgrade is not just about clawing back lap time in 2026. Under ADUO rules, Ferrari has two further evolutionary updates available before the current engine cycle ends, and the Monza specification, complete with the new turbo and the reworked combustion parameters around it, becomes the foundation for those steps. The first ADUO update of 2027 will effectively be a refined version of what debuts at Monza this weekend.
That reframes the whole exercise. Ferrari is not just trying to catch Mercedes before the season ends, it is trying to make sure it does not carry the same structural mistake into next year’s regulations. Getting the turbo right now matters more for what comes after 2026 than for what happens across the remaining 11 races, whatever the timing suggests to anyone hoping for an immediate Monza turnaround.
A Fix That Arrives Too Late to Matter Much This Year
Ferrari sits third in the constructors’ standings on 338 points, some way adrift of Mercedes on 425, and Hamilton and Charles Leclerc occupy P3 and P5 in the drivers’ championship respectively, with Hamilton 59 points off Kimi Antonelli at the top. Fixing a turbo that should have been right in January was never going to erase a deficit built up over 12 races, however sound the engineering behind it turns out to be.
What this upgrade really confirms is that Ferrari misjudged its own engine concept from the start, spent half a season racing around the consequences, and is only now using a regulatory loophole designed for gradual development to correct what was, in effect, a fundamental error. Monza will show whether the bigger turbo buys Ferrari lap time. It has already shown that the smaller one was never the clever idea it was sold as.
